Our 85 760 turbo abruptly stopped running. It would turn over but nothing happened. I checked for spark at the coil and the plugs -both had spark. Our hepful mechanic gave me telephone advice with which I found that the fuel pump was functional but was not coming on when the ignition switch was turned. I replaced the fuel pump relay but it did not help. Our mechanic told me how to bypass the safety switch in the ECU by shorting one of the relay poles to ground. The fuel pump comes on now when the ignition switch is turned, but it still won't start. Thus, it appears that I am getting spark, fule and air but it still won't start. There's pressure in the fuel line at the injector rack and the injectors appear to be functional. I cannot find anything that would block the air. Could the ECU have some function/malfunction that could keep it from starting?

Frustrated.